Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) days	Dec. 31, 2017 USD ($) days
Document Period End Date	Dec. 31, 2018
Repurchase Agreements	$ 75,717	$ 50,296
Weighted Average Interest Rate	2.79%	1.57%
Weighted Average Days to Maturity | days	49	116
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 21,431	$ 10,467
Maturity Overnight [Member]
Repurchase Agreements	19,450	5,250
30 Days or Less [Member]
Repurchase Agreements	$ 48,533	$ 19,771
Weighted Average Interest Rate	2.88%	1.59%
Weighted Average Days to Maturity | days	9	11
1 to 3 Months
Repurchase Agreements	$ 20,991	$ 16,150
Weighted Average Interest Rate	2.57%	1.50%
Weighted Average Days to Maturity | days	56	50
3 to 6 Months
Repurchase Agreements	$ 2,218	$ 7,287
Weighted Average Interest Rate	2.65%	1.50%
Weighted Average Days to Maturity | days	167	130
6 to 9 Months
Repurchase Agreements	$ 200	$ 2,361
Weighted Average Interest Rate	3.19%	1.66%
Weighted Average Days to Maturity | days	208	225
9 to 12 Months
Repurchase Agreements	$ 950	$ 202
Weighted Average Interest Rate	2.80%	1.64%
Weighted Average Days to Maturity | days	279	297
12 to 24 Months
Repurchase Agreements	$ 2,200	$ 1,700
Weighted Average Interest Rate	2.91%	1.84%
Weighted Average Days to Maturity | days	438	468
24 to 36 Months
Repurchase Agreements	$ 625	$ 2,200
Weighted Average Interest Rate	3.11%	1.80%
Weighted Average Days to Maturity | days	776	803
36 to 48 months
Repurchase Agreements	$ 0	$ 625
Weighted Average Interest Rate	0.00%	1.90%
Weighted Average Days to Maturity | days	0	1,141
FICC [Member]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 4,489	$ 2,698